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-rw-r--r--fs/namespace.c61
1 files changed, 34 insertions, 27 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index fc5002819..4fb1691b4 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -463,7 +463,6 @@ void __mnt_drop_write(struct vfsmount *mnt)
mnt_dec_writers(real_mount(mnt));
preempt_enable();
}
-EXPORT_SYMBOL_GPL(__mnt_drop_write);
/**
* mnt_drop_write - give up write access to a mount
@@ -1585,6 +1584,14 @@ static inline bool may_mount(void)
return ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN);
}
+static inline bool may_mandlock(void)
+{
+#ifndef CONFIG_MANDATORY_FILE_LOCKING
+ return false;
+#endif
+ return capable(CAP_SYS_ADMIN);
+}
+
/*
* Now umount can handle mount points as well as block devices.
* This is important for filesystems which use unnamed block devices.
@@ -1804,7 +1811,6 @@ int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg,
}
return 0;
}
-EXPORT_SYMBOL_GPL(iterate_mounts);
static void cleanup_group_ids(struct mount *mnt, struct mount *end)
{
@@ -1955,9 +1961,9 @@ static struct mountpoint *lock_mount(struct path *path)
struct vfsmount *mnt;
struct dentry *dentry = path->dentry;
retry:
- mutex_lock(&dentry->d_inode->i_mutex);
+ inode_lock(dentry->d_inode);
if (unlikely(cant_mount(dentry))) {
- mutex_unlock(&dentry->d_inode->i_mutex);
+ inode_unlock(dentry->d_inode);
return ERR_PTR(-ENOENT);
}
namespace_lock();
@@ -1968,13 +1974,13 @@ retry:
mp = new_mountpoint(dentry);
if (IS_ERR(mp)) {
namespace_unlock();
- mutex_unlock(&dentry->d_inode->i_mutex);
+ inode_unlock(dentry->d_inode);
return mp;
}
return mp;
}
namespace_unlock();
- mutex_unlock(&path->dentry->d_inode->i_mutex);
+ inode_unlock(path->dentry->d_inode);
path_put(path);
path->mnt = mnt;
dentry = path->dentry = dget(mnt->mnt_root);
@@ -1986,7 +1992,7 @@ static void unlock_mount(struct mountpoint *where)
struct dentry *dentry = where->m_dentry;
put_mountpoint(where);
namespace_unlock();
- mutex_unlock(&dentry->d_inode->i_mutex);
+ inode_unlock(dentry->d_inode);
}
static int graft_tree(struct mount *mnt, struct mount *p, struct mountpoint *mp)
@@ -2603,18 +2609,18 @@ static long exact_copy_from_user(void *to, const void __user * from,
return n;
}
-int copy_mount_options(const void __user * data, unsigned long *where)
+void *copy_mount_options(const void __user * data)
{
int i;
- unsigned long page;
unsigned long size;
+ char *copy;
- *where = 0;
if (!data)
- return 0;
+ return NULL;
- if (!(page = __get_free_page(GFP_KERNEL)))
- return -ENOMEM;
+ copy = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!copy)
+ return ERR_PTR(-ENOMEM);
/* We only care that *some* data at the address the user
* gave us is valid. Just in case, we'll zero
@@ -2625,15 +2631,14 @@ int copy_mount_options(const void __user * data, unsigned long *where)
if (size > PAGE_SIZE)
size = PAGE_SIZE;
- i = size - exact_copy_from_user((void *)page, data, size);
+ i = size - exact_copy_from_user(copy, data, size);
if (!i) {
- free_page(page);
- return -EFAULT;
+ kfree(copy);
+ return ERR_PTR(-EFAULT);
}
if (i != PAGE_SIZE)
- memset((char *)page + i, 0, PAGE_SIZE - i);
- *where = page;
- return 0;
+ memset(copy + i, 0, PAGE_SIZE - i);
+ return copy;
}
char *copy_mount_string(const void __user *data)
@@ -2679,6 +2684,8 @@ long do_mount(const char *dev_name, const char __user *dir_name,
type_page, flags, data_page);
if (!retval && !may_mount())
retval = -EPERM;
+ if (!retval && (flags & MS_MANDLOCK) && !may_mandlock())
+ retval = -EPERM;
if (retval)
goto dput_out;
@@ -2898,7 +2905,7 @@ SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
int ret;
char *kernel_type;
char *kernel_dev;
- unsigned long data_page;
+ void *options;
kernel_type = copy_mount_string(type);
ret = PTR_ERR(kernel_type);
@@ -2910,14 +2917,14 @@ SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
if (IS_ERR(kernel_dev))
goto out_dev;
- ret = copy_mount_options(data, &data_page);
- if (ret < 0)
+ options = copy_mount_options(data);
+ ret = PTR_ERR(options);
+ if (IS_ERR(options))
goto out_data;
- ret = do_mount(kernel_dev, dir_name, kernel_type, flags,
- (void *) data_page);
+ ret = do_mount(kernel_dev, dir_name, kernel_type, flags, options);
- free_page(data_page);
+ kfree(options);
out_data:
kfree(kernel_dev);
out_dev:
@@ -2941,9 +2948,9 @@ bool is_path_reachable(struct mount *mnt, struct dentry *dentry,
return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry);
}
-int path_is_under(struct path *path1, struct path *path2)
+bool path_is_under(struct path *path1, struct path *path2)
{
- int res;
+ bool res;
read_seqlock_excl(&mount_lock);
res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2);
read_sequnlock_excl(&mount_lock);